Tuesday, November 1, 2016

Some Pi fun...

Some Pi fun...  Raspberry Pi fun, that is. This is part of the project I'm working on with Mike B., my old navy buddy.  We're making some automated woodworking gear, and we chose the Raspberry Pi 3 Model B computer to drive it.  The first photo below shows my Raspberry Pi (the bottom board) with an Adafruit Stepper Hat attached (the top board).  The second photo shows the thing all hooked up to a stepper motor (the silver thing with a shaft sticking out of it).  This morning I built the stepper hat kit (a trivial matter of soldering some connectors on), hooked it all up, and ran the Python-based test software.  It was so boring – it all worked on the first try!

That stepper motor has 200 steps per revolution.  When I ran the test software, it had an option for “microstepping”, which I'd never heard of before.  The effect of this, on my test setup, was to multiply the number of steps by 8 – so 1,600 steps per revolution instead of 200.  Wow!  The more I read about microstepping, the more I realize how imperfect it is – but for at least one of the applications we have in mind, perfection is less important than smoothness, and microstepping helps a lot with that.  This bears more investigation...